Improved overshoe



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AUGUSTUS o. Bourin or cRANSToN, RHODE ISLAND.

Letters Patent No; 87,137,6latetl February 23, 1869.

IMPRQVED ovERsHoE.

The Schedule referred to in these Letters Patent and making part of the saule.

.Tov all whom,l it may concern:

Be -it known that I, AUGUSTUS O. BoURN, of the town of Cranston, in the county of Providence, and,

State of Rhode Island, have invented a new and useful Improvement in Overshoes; and I do hereby declare that the following specification, taken in connection with the drawings making a part of the sam'e, is a full, clear, and exact description thereof.

The object of the invention herein described is to produce an overshoe, of that class commonly known as Arctic overshoes, which shall, by preventing the ready admission ofwater from the outside, be practically water-tight, but shall, nevertheless, allow of the free escape of the insensible perspiration of the foot.

Shoes of the general class to which this belongs, are composed usually of a rubber sole, A, a rubber foxing, B, au outer vamp and quarters, C, of closelywoven cloth, an inner lining, a, of plush, or'other soft and loosely-woven material, tol give warmth to the foot, and an interlining of rubber between-the two walls of cloth. Usually the outside cloth and the inside lining are cemented together with rubber cement, but the inner lining, the outer cloth vamp, and an intermediate sheet of rubber, are secured together only at the edges, and

are elsewhere unattached.

The former mode of construction, as universally practised, produces a shoe which alike prevents the admission of water from without, and thev escape of perspiration from within.

The latter mode of construction secures ventilation to a considerable degree; but when the outer vamp and inner lining are not secured together throughout the Whole extent of their surfaces in contact, vthe vamp, after it has become wet, will shrink, and change its shape independent-ly of the lining, and render the shoe uncomfortable and unshapely.

lVhen rubber is spread out into a very thin and attenuated sheet, and applied to a shoe, as hereinafter described, it will not prevent the escape, through its pores, of moisture evolved by perspiration, generated, as such moisture is, under conditions which crea-te a pressure from the inside of the shoe, but water from the outside is, nevertheless, under the ordinary exposures of the slice from common use, practically ex eluded.

By availing myself of this fact, I am enabled to produce an overshoe which is suiiciently water-tight for the well-known solvents. This thin solution is applied to the cloth by means of a knife, in the samemanper in which rubber fabrics are usually coated by gun'i'n solution.

-The solution which I prefer to employ, is of such 'consistency that two coats upon the inside surface of the inner fabric, and two coats upon' the exterior of the lining, are requisite to be employed to render the two fabrics, when unit-ed, capable of furnishing sufficient protection against water from the outside.

Any person familiar with the art will be able ,readily to determine the thickness of the coatingE necessary, when it is understood that the rubber should be so thin that the color of the underlying cloth can be readily seen through it; in other words, -so thin that.

if a sack were made of a sheet of such thickness, filled with water and subject to gentle pressure, moisture would exude through it freely.

A skilled workman would probably be able to apply a coating of this character to a fabric by means of a calender, but it will be ordinarily safer to spread it by va knife,as above described.

I donot claim broadly the use of an interlining of rubber; neither do I claim broadly the use of an elastic fabric coated with rubber; but

What I claim as my invention, and desire to secure by Letters Patent, is-

rlhe `improvement in rubber-cloth overshoes, consisting of the interposition ot' a thin solution of rubber between the cloth upper and its lining, by which said fabrics are united and rendered practically water-proof, yet pervions to perspiration, substantially as-herein described.

AUGUSTUS O. BOURN. NVitncsses: i

JOHN D. THURSTON,

J AMES W. STILLMAN. 

